Mounjaro ‘golden dose’ hack sparks health warnings
Robert Price | Last update: 17th June 2025
Those of us who are using, or have used, Mounjaro have heard about the ‘golden dose’. This is medication left in the injection pen after the 4th, and final, prescribed dose has been used. Influencers, and users, have been talking on social media about using this dose as a 5th jab but doctors and healthcare professionals are warning against it – here’s our update.
What is the ‘golden dose’?
The term “golden dose” refers to a small amount of liquid left inside the Mounjaro KwikPen after the final prescribed dose has been taken. Some users, especially on TikTok and Reddit, have shared videos showing how to open the pen and extract this leftover using insulin syringes.
The goal? To squeeze out a “bonus” fifth dose.
This leftover isn’t a hidden extra left by Elli Lilly, the manufacturer. It’s known as an overfill. It’s built in to ensure each prescribed dose is delivered accurately and that the pen can be properly primed. Elli Lilly has been clear that this remaining overfill is not meant to be used and injected manually by users.
Why are people trying it?
We all know the cost of taking Mounjaro is meaningful. This is why many of us are interested in the idea of a 5th ‘bonus’ dose. Getting an extra jab from each pen could, in theory, mean savings of over £600 per year – so it’s not surprising some of us are tempted.
As Professor Naveed Sattar, an obesity expert at the University of Glasgow, explained in The Sun:
“These drugs are expensive and in demand – so some are trying anything to make them last longer.”
The risks of the golden dose
Doctors and healthcare providers want us to know the risks of the 5th dose trend:
Risk of infection
Mounjaro pens are sterile and intended for safe single-use injections. Once opened or tampered with, there’s a higher chance of contamination. Injecting leftover liquid can introduce harmful bacteria into the body, possibly leading to infections.
Unmeasured doses
The leftover medication isn’t a standard dose. Measuring it manually using a syringe is risky. You might inject too little, making the drug less effective, or too much, which increases the risk of side effects.
Taking too much Mounjaro
If you take too much Mounjaro, it can trigger more dangerous side effects. These include dehydration, gallbladder issues, and pancreatitis – a medical emergency that can be fatal in severe cases.
Official advice: Don’t do it
The UK healthcare regulator, Medicines and Healthcare products Regulatory Agency (MHRA), has issued their own warnings against tampering with injection pens. Dr Alison Cave, the MHRA’s Chief Safety Officer, stressed:
“Failure to follow dosage guidelines could harm your health or cause injury.”
The Mounajro manufacturer, Lilly, says: “Any excess solution in the pen after use should be discarded. It does not represent a full dose.”
Your health matters most
It’s tempting to save money by stretching your prescription further. But our message at SlimrChat is simple: safety comes first. Mounjaro is a powerful and effective treatment. As a prescription-only drug, it should be used under the supervision of your doctor or healthcare provider. Don’t be tempted to rely on social media hacks or sources of information, just like you should never buy drugs on social media from a non-verifiable source.